Solar System Log by Andrew Wilson, published 1987 by Jane's Publishing Co. Ltd.

ESA's Huygens Probe was delivered to Titan by the Cassini Orbiter in January 2005 after a dormant interplanetary journey of 6.7 years.

The probe started its descent through Titan's hazy cloud layers from an altitude of about 1,270 km. Huygens had to decelerate from 18,000 to 1,400 km per hour. A sequence of parachutes then slowed it down to less than 300 km per hour. At a height of about 160 km the probe's scientific instruments were exposed to Titan's atmosphere and at about 120 km the main parachute was replaced by a smaller one to complete the 2.25 hour descent.

The probe descended through haze until an altitude of about 30 km above the surface. This was around half the altitude suggested by pre-mission estimates of between 70 to 50 km above the surface.

At an altitude of 700 meters above the surface the descent lamp was activated. The purpose of this lamp was to not to illuminate the landing site, the light levels on the surface of Titan are roughly 1,000 times less than sunlight and 1,000 times stronger than a full moon, but to provide a monochromatic light source and enable scientists to accurately determine the reflectivity of the surface.

The surface phase of the mission lasted 1 hour and 10 minutes - considerably longer than had been anticipated. The landing on the surface was soft meaning no damage was done to the probe.